It's always good to approach a difficult problem with the eyes of someone new, but it's hard to actually get yourself into that mode. Google employee Hunter Walk suggests one way to tackle this problem is to pretend like you're a new employee every month.

The idea here is to keep yourself on your toes and have a fresh outlook on problem-solving. Putting yourself in the mindset of a new employee once a month means you're constantly refreshing your outlook. Walk has a few different ways to do this:

Why do we wait for the new employees to show up or let them have all the fun? What if you behaved like a new employee all the time? What if you dedicated the first day of each month to refreshing yourself for the next 30 days by saying "what am I going to do differently than I did last month?" What if you put yourself through your company's orientation program once a year in order to immerse yourself in the energy, optimism and nervousness of the new hires?

It's not a bad way to reboot your brain and keep your ideas fresh. If you look back to your first days of being a new employee and try to walk through those steps again (perhaps without the orientation), you might find yourself seeing problems from a new angle.